Databinding and included layouts: Cannot find setter attribute for onClick

I'm trying to set an OnClickListener for an <include>d layout, but receive a data binding error at compile time stating that data binding "Cannot find the setter for attribute 'android:onClick' with parameter type android.view.View.OnClickListener".

Context here is that I'm using data binding to inflate the included layout, so that I can pass values into it from a viewModel that I've bound to the including layout.

I've tried various syntax for the data binding expression:

@{viewModel::onClickFunction}
@{viewModel.onClickFunction}
@{() -> viewModel.onClickFunction()}
@{(view) -> viewModel.onClickFunction()}
@{_ -> viewModel.onClickFunction()}

I've tried all of the above with onClickFunction as a function, and also as an OnClickListener object.

Other related questions on Stack Overflow seem to solve this issue by cleaning the project to regenerate the databinding files, but that hasn't worked for me.

Relevant code snippets below:

viewModel

class MyViewModel() {
    val onClickFunctionAsAListener: OnClickListener = object:OnClickListener{
        override fun onClick(v: View?) {
            //Do something
        }
    }

    fun onClickFunction() {
            //Do something
    }
}

Including layout

<layout>

    <data>
        <variable name="viewModel" type="full.package.name.MyViewModel"/>
    </data>

    <LinearLayout>
        <include 
            layout="@layout/included_layout"
            android:onClick="@{viewModel.onClickListener}"
            app:customAttribute="@{`someText`}/>
    </LinearLayout>

</layout>

Included layout

<layout>

    <data>
        <variable name="customAttribute" type="String"/>
    </data>

    <TextView
        layout="@layout/included_layout"
        android:text="@{customAttribute}"/>

</layout>

Solution

It seems that you can't actually assign an OnClick handler to an <include> tag directly. I managed to get it to work by adding another variable to IncludedLayouts data binding class, and then assigning the OnClickListener to IncudedLayouts root view in XML.

After the changes, my files looked like this:

viewModel

class MyViewModel() {
    val onClickFunction: OnClickListener = object:OnClickListener{
        override fun onClick(v: View?) {
            //Do something
        }
    }
}

Including layout

<layout>

    <data>
        <variable name="viewModel" type="full.package.name.MyViewModel"/>
    </data>

    <LinearLayout>
        <include 
            layout="@layout/included_layout"
            app:onClick="@{viewModel.onClickListener}"
            app:customAttribute="@{`someText`}/>
    </LinearLayout>

</layout>

Included layout

<layout>

    <data>
        <variable name="customAttribute" type="String"/>
        <variable name="onClick" type="android.view.View.OnClickListener"/>
    </data>

    <TextView
        layout="@layout/included_layout"
        android:text="@{customAttribute}"
        android:onClick="@{onClick}"/>

</layout>